This is something you need to discuss with your doctor.
Tums are an antacid that people use for indigestion and not indicated for use with constipation.
Have you been diagnosed with IBD?
You really need to talk your GI about treatment.
Feel better soon
Hugs and best wishes
Trysha

Us crohnies must stick together.
Constipation can occur with crohn's and it is possible your medication needs a review.
Don't put up with the discomfort.Talk to your GI .
I have encountered similar problems and my GI prescribed Mucillium,made form psyllium seeds. , which I have found to be very gentle and effective.
It might work for you but you need to be supervised by the GI if doing this.
No one thing agrees with everyone.
It is a soluble fibre which keeps the intestinal motility running smoothly.
My crohn's is in the left colon just above the sigmoid.
Another thing I am trying is bone broth which I make from scratch.(so far so good)
Any animals bones will do, I have used beef and also lamb bones., can also use chicken.
Very simple to make---just cover the bones with water and boil for many hours-
I do it for 8-12hrs but the longer the better.
You can add vegetables at any stage and I do at the beginning of cooking slice onion and some garlic into the pot, maybe carrot etc.
At the end of the 8-12 hours I strain off the solids and discard them,then place the broth in the frig and later skim off the fat.Makes a good clear broth to drink and is very nourishing.If you want veg can be added and cooked in it for a meal also.
It adds to the mineral content if veg is added in the last 30-40mins.,if you don't want to strain it.Some people cannot tolerate some of the vegs.
It is supposed to be anti inflammatory among other good nutritional values.
If you google bone broth you will find good recipes listed.
Hope you talk to your GI for some help.
Feel better soon
Hugs and best wishes
Trysha